May 7 (Reuters) - Diagnostics firm Bio Rad Laboratories reiterated its 2024 sales growth forecast on Tuesday, weighed by persistently weak spending by biotech companies and sluggish demand in China.

The supplier of laboratory apparatus and instruments for drug manufacturers and biotech companies continues to see adjusted revenue growth for the full-year between 1% and 2.5% on a currency-neutral basis.

Large rival Thermo Fisher Scientific slightly bumped up its annual profit forecast in April while Waters Corp left its outlook for the year unchanged as it remains cautious about a recovery in its key markets.

Subdued spending in the biotech sector as well as sluggish demand in the key China market has hit Bio-Rad's life sciences segment sales, offset by an increase in demand for its clinical diagnostics products.

The Hercules, California-based company continues to be cautiously optimistic about a gradual recovery in the biopharma market in the second half of the year.

Sales from its life sciences unit, which makes products for biotech, pharmaceutical and food testing clients, fell 25.3% to $241.7 million.

On an adjusted basis, Bio-Rad recorded a per-share profit of $2.29 for the quarter ended March 31, marginally above analysts' estimate of $2.15.

Shares of the company fell 1.4% to $276 in after market hours. (Reporting by Unnamalai L in Bengaluru; Editing by Alan Barona and Shailesh Kuber)